At the last Tokyo Game Show, Capcom showed footage of Resident Evil 5 (PS3, Xbox 360), which ended with a shot of Jill Valentine's tombstone. If you remained hopeful that Capcom was just pulling your leg and didn't kill off Jill, I have some bad news for you.

The latest issue of Famitsu features a 2-page ad of Resident Evil 5, showing Chris Redfield paying & placing flowers his respects over Jill's tombstone, his ex-partner from the original Resident Evil .Capcom offers no hints on how she died, but seeing how they deemed it important enough to be the centerpiece of a 2-page ad, I'm guessing her death will play a part in the story of RE5.

Few deaths in the video game world actually matter in the world of video games, so it'd just be a shame if Capcom didn't elaborate on it. Then again, is she really dead? Ohhhh. I'll leave that up to the conspiracy theorists. Here's the vid from TGS showing Jill's tombstone for reference, since it wasn't "officially" released:
from TGS 2008, many gamers missed this ...............

no its a grave of jill they havent found the body so they just think shes dead, that was before the africa incident, then noticed she was alive because Wesker was using her. so no worry the cool chick is still alive.